Abstract: A crosslinkable rubber composition includes, as essential components: (A) an ethylene-?-olefin-nonconjugated polyene random copolymer rubber in which the nonconjugated polyene has a terminal vinyl group-containing norbornene compound represented by the following general formula (1) or (II), wherein n is an integer of 0 to 10, R1 is H or an alkyl group, and R2 is H or an alkyl group, wherein R3 is H or an alkyl group, and which has a viscosity of not less than 10 Pa·s and less than 1,000 Pa·s at 25° C. under a shear rate of 10 s?1; (B) an organopolysiloxane which has three repeating units of siloxane represented by the following formula and which has three Si-bonded hydrogen atoms per molecule, wherein R4 is a monovalent hydrocarbon group; (C) a reinforcing filler; (D) a curing catalyst; and (E) a curing reaction retarder.